It is well known to deliver fluids, such as adhesives, from a spraying system for various purposes. Such known spraying systems are disclosed, for example in U.S. Pat. No. 5,419,491 issued to Breitsprecher on May 30, 1995 titled TWO COMPONENT FLUID SPRAY GUN AND METHOD and in U.S. Pat. No. 5,639,027 issued Jun. 17, 1997 to Fritz titled TWO COMPONENT EXTERNAL MIX SPRAY GUN. Such known spray systems include using air pressure to propel or convey one fluid component and air to propel another fluid component. The two components are mixed and applied to a surface to be coated with the fluids.
One such known spraying system includes a two component external mix spray gun that requires a pneumatically operated valve for delivering a catalyst into pattern shaping air passages in the barrel of the gun. The valve opens in response to pressure created by opening a unitary chamber for a pattern shaping air passage and an atomization air passage. Before opening an adhesive fluid valve for delivering an adhesive of such known gun, a manual trigger operates air valves to provide atomization air and the pattern shaping air. The valve is then opened (prior to the opening of the adhesive fluid valve) in response to an increase in air pressure downstream from the air valves (i.e., in response to the operation of the trigger and the presence of the flow of the pattern shaping air) to inject the catalyst into pattern shaping air passages. Then, external to such known spray gun, the catalyst is brought into contact with the adhesive, which is "atomized" by the atomization air and the pattern shaping air. However, a problem with such known guns is that the manual trigger may not fully open the adhesive fluid valve, which may result in an inconsistent and ineffective ratio of the catalyst to the adhesive and "clogging" of the gun.
Another known spraying system includes an air-operated fluid spray gun for mixing multiple fluids together almost simultaneously to deposit the mixture on a surface. Such mixing and deposition is accomplished by first directing an atomized stream of adhesive fluid axially out of the end of the barrel of the gun and toward the surface to be coated. An atomized stream of activator fluid is then injected generally radially into the adhesive stream so that the activator and adhesive streams mix thoroughly and the mixture is almost simultaneously deposited on the surface. In such known spray guns, the activator fluid is discharged from fluid nozzles. However, a problem with such known spray guns is that the activator is turned on before the adhesive is turned on, which may result in an incorrect ratio of a volume of adhesive to a volume of activator fluid and "clogging" of the gun.
Accordingly, it would be advantageous to provide a fluid spraying system that provides for the independent control of the flow of the various fluids. It would also be advantageous to provide a fluid spraying system that provides for improved atomization of the activator fluid, for example with fan air within the fan air passages of an air cap. It would further be advantageous to provide a fluid spraying system that is intended to be simple to assemble, maintain and service. It would also be advantageous to provide a fluid spraying system that provides a suitable ratio of activator to adhesive. Other advantages of the subject matter recited in the claims will become apparent to those skilled in the art upon review of the specification and the appended claims.